By DAN DUGGAN

January 20, 2013

The Baltimore Ravens’ backup linebacker Brendon Ayanbadejo referred to it as a “gimmick” ahead of the teams’ matchup in the A.F.C. Championship game Sunday at Gillette Stadium.

In October, Jets linebacker Calvin Pace called it “borderline illegal.”

While the Patriots’ offense has its critics, many have hailed its unparalleled efficiency. New England led the N.F.L. in scoring with 557 points; the Denver Broncos were a distant second with 481.

Piling up points is nothing new for the Patriots — this is the third time in the last six seasons they have led the league in scoring — but their offense has garnered even more attention because of a hurry-up attack that can leave opposing defenses dizzy.

But have the Patriots radically changed anything? Not according to Bill O’Brien, who was an offensive assistant for five seasons with the Patriots before becoming the coach at Penn State last January.

“I don’t think it’s anything different,” O’Brien said.

O’Brien noted that the fast-paced elements were in place when he arrived with the Patriots in 2007 as an assistant under the current offensive coordinator Josh McDaniels.

“Maybe they’ve added some wrinkles to it like they do every single year,” O’Brien said. “That’s what makes the New England coaching staff so good is that they never stay the same. Maybe you could say that, but as far as no-huddle and tempo and all those things, I think they’ve been doing that for a long time.”

There are statistics that suggest the offense has been ramped up this season, but those can be misleading.

The Patriots ran 1,191 plays this season, 8 short of the N.F.L. record the franchise set in 1994. And they ran them quickly, averaging a play every 24.9 seconds, more than one second faster than the next team.

O’Brien said other factors, primarily the score, affect the total number of plays. When he was with the Patriots, there was always one goal, and it was not to rack up snaps.

“The mentality on offense in New England is that every time we touch the ball we want to score a touchdown that series,” O’Brien said. “That was the No. 1 deal.”

Matt Chatham, a linebacker for the Patriots from 2000 to 2005, said the speed of snaps is skewed by the fact that the Patriots do not often huddle between plays, although they are not necessarily trying to push the pace.

“You’re just naturally going to use less of the clock in that environment,” Chatham said. “When you don’t huddle, you save about 10 seconds. The tempo doesn’t really change, though.”

The Patriots’ up-tempo attack has drawn more attention this year because of a link to the new Philadelphia Eagles coach Chip Kelly, who engineered a blindingly fast and prolific spread offense at Oregon.

Kelly and O’Brien have been friends for 20 years and regularly discuss football strategies. In the summer of 2011, on Kelly’s way home to Manchester, N.H., he stopped at the Patriots’ facility to exchange ideas with Coach Bill Belichick and staff members.

“There’s a lot of give-and-take in coaching, and Chip was a guy that we talked to and gave him some things, and he gave us some things,” O’Brien said. “That’s about as far as it went.”

Kelly declined a request to be interviewed for this article, but in October in The Oregonian he called his influence on the Patriots’ offense “overblown.” That notion is supported by the fact that McDaniels, who is responsible for installing the play calls, was not on the Patriots’ staff at the time of the meeting.

“Certainly, New England is not running Oregon’s offense,” O’Brien said. “Maybe there were a couple of things that we took from that, but New England’s offense is what it’s always been, and it’s run very well by Josh and then Tom Brady on the field.”

Regardless of how many of Kelly’s schemes were adopted, the meeting exhibited Belichick’s openness to different ideas. He has well-documented relationships with the decorated college coaches Nick Saban and Urban Meyer, and his circle extends beyond football. O’Brien recalled visits from Boston Celtics Coach Doc Rivers, the former Boston Red Sox Manager Terry Francona and even Paul Assaiante, who led the Trinity squash team to 252 consecutive victories from 1998 to 2012.

“He’s just a really creative guy that gets opinions of winning coaches from all different sports,” O’Brien said of Belichick. “That’s one of the reasons why he’s the best. One thing about Bill is he’s a great listener. He has definite beliefs in his football philosophy, but he’s also a guy that allows coaches and definitely himself to think out of the box.”

Correction: January 20, 2013

An earlier version of this article reported an incorrect number of plays by which the Patriots fell short of reaching the N.F.L. record that the franchise set in 1994, which is 1,199 plays. The Patriots were eight plays short of the record, not nine.